Seth:-
> Every Class is a subClass of that which is
> named Thing.
Some classes don't hve sub classes, or super classes, but all are of
rdf:type rdfs:Class. rdfs:Class is an rdfs:Class, in fact. Still,
rdf:Class is a subClass of rdf:Resource, indicating that there are
things that are resources, but not classes... literals and the like I
guess.
As for URIs, they identify resources... I don't think that RDFS uses
the word resource in the same context as the URI specification. Of
course, RDFS also doesn't recognize that literals are in fact URI
strings (data:,) and so literals technically can be used as subjects
and predicates, although that wouldn't make much sense. There are many
complications like this.
William's right that some things are not identifiable things, but
things are always a bit thingy on the primitive side of things. In
other words, where primitives in RDF and other similar KR language are
concerned, all we need worry about is that the system works; CWM will
still work for me tomorrow if someone defines that all URIs are a type
of pizza identifier. So, let's not get bogged down in "what is a
definition of is" and so forth, when pragmatically it's not all that
important. Agreement about URIs is more important than some conceptual
definition lying around on some hard drive.
--
Kindest Regards,
Sean B. Palmer
@prefix : <http://webns.net/roughterms/> .
:Sean :hasHomepage <http://purl.org/net/sbp/> .